Sökning: "Sodium hydroxide"

Visar resultat 6 - 10 av 55 avhandlingar innehållade orden Sodium hydroxide.

1. 6. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

   Författare :Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alkali; carboxymethyl cellulose; cellulose I; cellulose II; cellulose dissolution; degree of substitution; enzymatic treatment; filterability; gel formation; mercerization; multivariate analytical methods; NIR FT Raman spectroscopy; sodium hydroxide; zink oxide; Chemical Engineering; Kemiteknik;

   Sammanfattning : This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. LÄS MER

3. 7. Fouling and cleaning of solid surfaces. The influence of surface characteristics and operating conditions

   Författare :Camilla Karlsson; Livsmedelsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Food and drink technology; ellipsometry; sodium hydroxide; anionic surfactant; betalactoglobulin; protein; stainless steel; hydrophilic surface; hydrophobic surface; cleaning; adsorption; fouling; Livsmedelsteknik; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

   Sammanfattning : The severe fouling common in food processing puts high demands on equipment cleaning. Adsorption of the protein betalactoglobulin to solid surfaces and its subsequent removal were followed using in situ ellipsometry. Most experiments were done in a stirred cuvette. Additionally, a flow cell was designed, which was employed in some work. LÄS MER

4. 8. Some factors affecting the amount of residual phase lignin during kraft pulping

   Författare :Mikael E. Lindström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deligniflcation; Residual phase lignin; Hydrogensulfide ion; Hydroxide ion; Polysulfides; Ionic strength; Temperature; Lignin; Kraftpulping; Selectivity; viscosity; Kappa number; chemical degradation; Disproportionation; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : The amount of lignin which needs to be removed according to the slow residual delignification phase in kraft pulping, i e residual phase lignin, has been studied as a function of the process conditions. The variebles studied were the concentrations of hydroxide ions, hydrogensulfide ions, sodium ions (ionic strength) and temperature. LÄS MER

5. 9. Surface characterization of the chromium hydroxide and basic calcic deposition layers formed on the steel cathode in the chlorate production process

   Författare :Annika Ahlberg Tidblad; KTH; []
   Nyckelord :;

   Sammanfattning : During technical service, the surface of the steel cathodein the chlorate production process changes with respect tochemical composition and morphology. Deposition of insolublespecies from the electrolyte and corrosion products from thebase metal accumulate and form surface layers that influencethe cathode activity with regards to hydrogen evolution, theprimary reaction, as well as to various parasitic reactions. LÄS MER

7. 10. Carbohydrate degradation and dissolution during Kraft cooking : Modelling of kinetic results

   Författare :Dan Johansson; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kraft cooking; softwood; hardwood; cellulose; xylan; glucomannan; degradation; dissolution; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

   Sammanfattning : Chemical pulp fibres from wood are commonly used in products associated with packaging as well as with printing and writing. The prevalent way of liberating fibres is by subjecting wood chips to Kraft cooking. This process has a history of almost 130 years and should be both well described and well established. LÄS MER